let x1, . . . , x20 be independent poisson random variables with mean 1. p=P(20Σi=1 Xi ≥ 15)
(a) Use Markov's inequality to obtain an upper bound on p. (b) Use Chebyshev's inequality to obtain an upper bound on p. (c) Use the central limit theorem to approximate p. (d) Find the exact probability p.